Flavor is an important quality criterion for virgin olive oils. The identification of the compounds causing the flavor or off-flavor therefore is the key for quality control. Their analysis in olive oils usually requires more or less cumbersome sample preparation like liquid/liquid extraction, solid phase extraction or distillation techniques, often with the drawback of organic solvent use. Headspace and purge & trap methods do not use organic solvents, but their analyte range is restricted to the volatiles and therefore characterizes more the compounds contributing to aroma/smell of a sample, not the flavor/taste.

Direct thermal extraction of olive oil in an inert atmosphere under controlled temperature conditions can be used to easily analyze the volatile and semi-volatile compounds contributing to flavor. 10 μl of olive oil are injected into an empty glas tube and inserted into a thermal desorption unit (TDS). The TDS was ramped to 80°C with high desorption flow, allowing the analytes to be transferred into a PTV-liner and trapped at sub-ambient temperatures (-150°C), while retaining the oil-matrix in the TDS tube. After completion of sample transfer, the PTV was ramped to 280°C, releasing the extracted compounds into a GC-MS system for subsequent analysis at very high sensitivity.

Thermal Desorption System (TDS)

The GERSTEL Thermal Desorption System (TDS) is a flexible multi-functional system for highly sensitive determination of volatile and semi-volatile organic compounds (VOCs and SVOCs) that have been trapped on adsorbent tubes or on GERSTEL Twisters.

The TDS is also frequently used for direct thermal extraction and determination of VOCs and SVOCs from solids without sample preparation. Application examples are natural products, flavor and fragance, emssions from materials that are used indoors in buildings or in automobiles, semiconductors, polymers and packaging.